Friday, July 06, 2007

The recent developments in the understanding of hadron mass spectrum involve the realization that hadronic k=107 space-time sheet is a carrier of super-canonical bosons (and possibly their super-counterparts with quantum numbers of right handed neutrino) (see this) . The model leads to amazingly simple and accurate mass formulas for hadrons. Most of the baryonic momentum is carried by super-canonical quanta: valence quarks correspond in proton to a relatively small fraction of total mass: about 170 MeV. The counterparts of string excitations correspond to super-canonical many-particle states and the additivity of conformal weight proportional to mass squared implies stringy mass formula and generalization of Regge trajectory picture. Hadronic string tension is predicted correctly. Model also provides a solution to the proton spin puzzle.

In this framework valence quarks would correspond to a color singlet state formed by space-time sheets connected by color flux tubes having no Regge trajectories and carrying a relatively small fraction of baryonic momentum. This kind structure, known as Pomeron, was the anomalous part of hadronic string model. Valence quarks would thus correspond to Pomeron.

1. Experimental evidence for Pomeron

Pomeron originally introduced to describe hadronic diffractive scattering as the exchange of Pomeron Regge trajectory [1]. No hadrons belonging to Pomeron trajectory were however found and via the advent of QCD Pomeron was almost forgotten. Pomeron has recently experienced reincarnation [2,3,4]. In Hera e-p collisions, where proton scatters essentially elastically whereas jets in the direction of incoming virtual photon emitted by electron are observed. These events can be understood by assuming that proton emits color singlet particle carrying small fraction of proton's momentum. This particle in turn collides with virtual photon (antiproton) whereas proton scatters essentially elastically.

The identification of the color singlet particle as Pomeron looks natural since Pomeron emission describes nicely diffractive scattering of hadrons. Analogous hard diffractive scattering events in pX diffractive scattering with X=anti-p [3] or X=p [4] have also been observed. What happens is that proton scatters essentially elastically and emitted Pomeron collides with X and suffers hard scattering so that large rapidity gap jets in the direction of X are observed. These results suggest that Pomeron is real and consists of ordinary partons.

2. Pomeron as the color bonded structure formed by valence quarks

In TGD framework the natural identification of Pomeron is as valence The lightness and electro-weak neutrality of Pomeron support the view that photon stripes valence quarks from Pomeron, which continues its flight more or less unperturbed. Instead of an actual topological evaporation the bonds connecting valence quarks to the hadronic space-time sheet could be stretched during the collision with photon.

The large value of αK=1/4 for super-canonical matter suggests that the criterion for a phase transition increasing the value of Planck constant (this) and leading to a phase, where αK propto 1/hbar is reduced, could occur. For αK to remain invariant, hbar0→ 26×hbar0 would be required. In this case, the size of hadronic space-time sheet, "color field body of the hadron", would be 26× L(107)=46 fm, roughly the size of the heaviest nuclei. Note that the sizes of electromagnetic field bodies of current quarks u and d with masses of order few MeV is not much smaller than the Compton length of electron. This would mean that super-canonical bosons would represent dark matter in a well-defined sense and Pomeron exchange would represent a temporary separation of ordinary and dark matter.

Note however that the fact that super-canonical bosons have no electro-weak interactions, implies their dark matter character even for the ordinary value of Planck constant: this could be taken as an objection against dark matter hierarchy. My own interpretation is that super-canonical matter is dark matter in the strongest sense of the world whereas ordinary matter in the large hbar phase is only apparently dark matter because standard interactions do not reveal themselves in the expected manner.

3. Astrophysical counterpart of Pomeron events

Pomeron events have a direct analogy in astrophysical length scales. I have commented about this already earlier. In the collision of two galaxies dark and visible matter parts of the colliding galaxies have been found to separate by Chandra X-ray Observatory.

Imagine a collision between two galaxies. The ordinary matter in them collides and gets interlocked due to the mutual gravitational attraction. Dark matter, however, just keeps its momentum and keeps going on leaving behind the colliding galaxies. This kind of event has been detected by the Chandra X-Ray Observatory by using an ingenious manner to detect dark matter. Collisions of ordinary matter produces a lot of X-rays and the dark matter outside the galaxies acts as a gravitational lens.

4. Super-canonical bosons and anomalies of hadron physics

Super-canonical bosons suggest a solution to several other anomalies related to hadron physics. Spin puzzle of proton has been already discussed in previous postings.

The events observed for a couple of years ago in RHIC (see this) suggest a creation of a black-hole like state in the collision of heavy nuclei and inspire the notion of color glass condensate of gluons, whose natural identification in TGD framework would be in terms of a fusion of hadronic space-time sheets containing super-canonical matter materialized also from the collision energy. The blackhole states would be blackholes of strong gravitation with gravitational constant determined by hadronic string tension and gravitons identifiable as J=2 super-canonical bosons. The topological condensation of mesonic and baryonic Pomerons created from collision energy on the condensate would be analogous to the sucking of ordinary matter by real black-hole. Note that also real black holes would be dense enough for the formation of condensate of super-canonical bosons but probably with much large value of Planck constant. Neutron stars could contain hadronic super-canonical condensate.

In the collision, valence quarks connected together by color bonds to form separate units would evaporate from their hadronic space-time sheets in the collision just like in collisions producing Pomeron. The strange features of the events related to the collisions of high energy cosmic rays with hadrons of atmosphere (the particles in question are hadron like but the penetration length is anomalously long and the rate for the production of hadrons increases as one approaches surface of Earth) could be also understood in terms of the same general mechanism.

5. Fashions and physics

The story of Pomeron is a good example about the destructive effect of reductionism, fashions, and career constructivism in the recent day theoretical physics.

For more than thirty years ago we had hadronic string model providing satisfactory qualitative view about non-perturbative aspects of hadron physics. Pomeron was the anomaly. Then came QCD and both hadronic string model and Pomeron were forgotten and low energy hadron physics became the anomaly. No one asked whether valence quarks might relate to Pomeron and whether stringy aspects could represent something which does not reduce to QCD.

To have some use for strings it was decided that superstring model describes not only gravitation but actually everything and now we are in a situation in which people are wasting their time with AdS/CFT duality based model in which N=4 super-symmetric theory is decided to describe hadrons. This theory does not contain even quarks, only spartners of gluons, and conclusions are based on study of the limit in which one has infinite number of quark colors. The science historians of future will certainly identify the last thirty years as the weirdest period in theoretical physics.

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About Me

I am a Finnish theoretical physicist. For last 37 years Topological Geometrodynamics has been both the passion and mission of my life. TGD is a noble attempt to construct a theory of everything, not forgetting consciousness. I have four children, who have brought a lot of happiness to my life. I live in Hanko, a small seaside town in southern Finland. I love almost all kinds of music but if I had to give just one name I would have difficulties in deciding between Chopin and Beethoven.

The 37 years with TGD have produced an enormous amount of material covering basic
TGD as a mathematical theory, the applications of TGD ranging from Planck length scale
to cosmology, and TGD inspired theory of consciousness and of living matter as a macroscopic
quantum system. I have organized this material at my homepage as online books and articles.